whole house audio power question

John Titan · 12-11-2005, 09:35 PM

Hey everyone,

Heres my question that I hope someone can answer. I have an 8-zone whole house audio system with a sony receiver powering it at 100 WPC. Each zone has a stereo impedece matching volume control made by russound.Is there a formula for figuring how many watts are actually getting to each speaker.Do I just divide 100 watts by 8 for each channel or is there a more scientific way of figuring it out.I have radio shack in-ceiling speakers that are rated for about 40 WPC. I have the receiver set at about half volume and have at times put the volume controls at max. The speakers seem to handle it fine and put out a pretty good volume (They sound pretty good for cheap speakers. Most are 6.5" single point stereos).

Thanks for any help

Grant B · 12-15-2005, 01:27 AM

Quote:

I have an 8-zone whole house audio system with a sony receiver powering it at 100 WPC.

I think you might have some terms mixed up. 8 zones means you can play 8 different sources independently of each other

Do you have 8 pairs of speakers or 8 speakers total?
Each is connected to a 100wpc sony?

Quote:

Do I just divide 100 watts by 8 for each channel

No since it's watts per channel and it has 8 channels or 800 watts total

John Titan · 12-15-2005, 07:48 AM

No it's a single source.Whatever input I select on the receiver is what plays through the whole house. It's kinda like running 8 pairs of speakers off of a stereo reciver. The volume controls are impeadence matching so they have little transformers in them that don't allow the ohms to drop below 6-8 ohms.
I have it set up like this, the recievers left and right channel go into the connecting blocks (EZB-1+EZB-2 made by russound). A wire (16-4)is ran from the connecting block to each of the 8 volume controls (ALTX-2D also made by russound) from there a wire is run to each speaker. Alowwing you to control the volume in each zone (or room).

Hope this helps
Thanks for any input
John

Philip Hamm · 12-15-2005, 07:52 AM

I have a similar setup, but with only two "pairs" of speakers (two Single Point Stereo speakers like yours). I have no idea how to calculate the wattage going to each one.

You're presenting an extremely difficult load to your receiver, even with the impedence matched volume controls. Keeping the volumes maxed out and controlling the volume with your reciever is the Right Thing To Do. You might fry your receiver if you run it loud and often, or your receiver may be able to handle the load no problem.

I wouldn't worry about wattage numbers. The speakers are in no danger, the receiver is what I'd worry about. Either is fairly readily replacable. You can get old stereo receivers on Ebay for real cheap that will power some of your speakers easily.

John Titan · 12-15-2005, 10:35 AM

I've had it hooked up like this for about a year. The reciever seems to handle it fine. I have a small fan in the closet with the reciever to help contol the heat. I never really put it up to loud it's more for backround music.(one cool thing I did was run a couple of outputs from my reciever in the basement so when I have a party and people are singing karaoke you can here it up stairs too. Makes for a good laugh!) Another thing I did was run cat-5 with all the speaker wire because I really want to get an a-bus system with the amplified volume controls ,also allows for 4 sources. Some time in the future I plan to upgrade.

John

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Scott Mullen · 12-16-2005, 10:14 AM

Have you tried using a Digtal VOM to look and see what the actual impeadance is that the receivers output sees???

I would think that an impedece matching speaker selector would try to keep a fairly level load thats close to what your receiver would like to see... If setup right...

John Titan · 12-16-2005, 10:38 AM

Hey scott,

Would that help me figure out the amount of watts going to each speaker. If so, how would i do that?

Thanks

John Titan · 12-16-2005, 10:44 AM

A VOM is a multi-meter right? I have a cheaper analog one?
Could I use this ?

Grant B · 12-17-2005, 08:16 PM

VOM = volt ohm meter
DMM = digital multi meter

same thing but one has numbers
Yes yours will work fine